Hydraulically actuated piercing unit



Sept. 8, 1964 M. WILLIAMSON HYDRAULICALLY ACTUATED PIERCING UNIT Filed Feb. 24, 1961 ZM W/ HITOF/YEY-S- United States Patent 3,147,657 HYDRAULICALLY ACTUATED PIERCING UNIT Floyd M. Williamson, 2405 E. Grand Blvd Detroit 11, Mich. Filed Feb. 24, 1961, Ser. No. 91,362 2 Claims. (Cl. 83140) This invention relates to a hydraulically actuated piercing unit for a ram type press and has particular reference to a piercing unit which is so designed as to facilitate proper alignment of the punch with the cooperating die member and removal of the punch for sharpening or replacement without the necessity of removing the entire unit from its location on the press.

A hydraulically actuated piercing unit is frequently used in a press when it is desired to effect a piercing operationin a direction other than that in which the ram of the press travels, and a unit of this type may also be used as a portable piercing unit actuated by a suitable source of fluid under pressure. After a unit of this type is installed, it is often difficult to remove in the event that it is necessary to replace the punch or to remove it for sharpening. According to the present invention the unit is so designed that the punch may be removed without removing the entire unit, and it is also so constructed as to enable rotation of the punch to orient the punch relative to the die member with which it cooperates and to thereafter lock the punch in place. The unit is also provided with a stripper member which is adapted to clamp the work against the die prior to engagement of the punch with the work.

A principal object of the invention is to provide a new and improved hydraulically actuated piercing unit for use Other and further objects of the invention will be ap-' parent from the following description and claims and may be understood by reference to the accompanying drawing, which by way of illustration shows a preferred embodiment of the invention and what I now consider to be the best mode of applying the principles thereof. Other embodiments of the invention may be used without departing from the scope of the present invention as set forth in the appended claims.

The drawing discloses a piercing unit -which is actuated by a hydraulic control system 12. The piercing unit comprises a body 14 having a cylinder bore 16 opening from one end thereof and closed by an end plate 18 which is secured to the body 14 by screws 20. A piston 22 is reciprocable within the bore 16 and includes a seal 24 which is clamped against the piston by a washer 26 and a socket head screw 28. The screw 28 is threaded into the inner end of a piston rod 30 which extends through the reduced diameter bore 32 at the other end of the body 14. A seal 34 is provided at the outer end of the bore 32 to seal the interior of the unit.

The outer end of the piston rod 30 is provided with a socket 36 which receives the inner end of the punch 38. A set screw 40 is threaded into a radially extending threaded hole in the outer end of the piston rod 30 and engages the punch 38 to secure the punch within the socket A collar 42 is seated against the shoulder 44 which de fines the end of the bore 16. The collar 42 is provided with a key 46 which extends into a groove 48 on the piston rod 30 so that the piston rod is nonrotatable relative to the collar 42 but is axially slidable through the collar.

A spacer sleeve 50 is seated against the collar 42 and is adapted to be engaged by the piston 22 to determine the length of the stroke of the punch 38. A spring 52 is confined between the collar 42 and the piston 22 and returns the piston to its retracted position after the punch operation is completed.

- per member 54. The punch 38 extends through an aperture 60 in the end wall 58 of the stripper member 54. The stripper member is provided with an annular groove 62 on its inner wall and an elongated slot 64 which intersects the groove 62. The set screw 40 is inserted through the slot 64. The outer end of the piston rod may be provided with a series of semi-spherical recesses each receiving a ball 66. The balls 66 are adapted to roll along the groove 62 as the stripper member slides along the piston rod and limit the travel of the stripper member relative to the piston rod.

The hydraulic control system includes a tank 70 containing hydraulic fluid maintained under pressure by compressed air supplied through a line 72. The hydraulic fluid is supplied to the cylinder 16 under the pressure at which it is maintained within the tank 70 through a line 74 leading to a passage 76 in a valve body 78 having a valve chamber 80 therein. A sleeve 82 is located in the chamber 80 and is provided with a series of radial ports 84 and a second series of radial ports 86. A passage 88 intersects the chamber 80 and the sleeve 82 is of reduced diameter in the region of the ports 84 and 86. A valve member is reciprocable within the sleeve 82 between an upper position in which the ports 84 are closed while the ports 86 are opened and a lower position in which the ports 86 are closed while ports 84 provide communication between the passages 76 and 88 in the valve body 78. The valve member 90 is urged to its lower position by a spring 92. With the valve member in its lower posi-" tion the hydraulic fluid under pressure in the tank 70 is supplied through passage 76 to the interior of the sleeve 82 and through radial ports 84, passage 88, and conduit 94 to the bore 16.

The control system includes a booster unit comprising a work cylinder 102 having a piston 104 therein and an air cylinder 106 having a larger diameter piston 108 therein, the pistons 104 and 108 being connected by a stem 110. A passage 112 provides communication between the work cylinder 102 and the lower end of the sleeve 82. The work cylinder 102 is adapted to be filled with fluid under pressure from the tank 70 through a line 114 past a check valve 116 and through line 118 and passage 112 to the' of the press so as to actuate the piercing unit in timed' relation to the operation of the press. The valve 122 is adapted to connect the air cylinder 106 with the air pressure line 120, as shown in the drawing, and is also movable to a position in which the line 124 is connected to the exhaust line 126.

When the ram of the press is raised, the valve 122 connects the cylinder 106 to the exhaust line 126 whereupon the hydraulic fluid is supplied to the upper end of the work cylinder 102 past the check valve 116 thereby moving the booster pistons to their lower position. Both sides of the valve member 90 will be subjected to the same hydraulic pressure at this time and the spring 92 will force the valve member to its lower position thereby opening the ports 84 so that hydraulic fluid is supplied to the bore 16. The strength of the spring 52 is such that the pressure of the hydraulic fluid in the tank 70 is not sufficient to move the piston 22 of the piercing unit to its extended position. As soon as the valve 122 is operated by the ram or some other movable part of the press to connect the lines 120 and 124, air under pressure will be supplied to the cylinder 106 and, since the piston 108 has a considerably larger diameter than the piston 104, the booster pistons will be forced upwardly forcing the hydraulic fluid from the work cylinder 102 out through the passage 112. The check valve 116 prevents return flow of this trapped fluid back to the tank 70. The fluid ejected from the cylinder 102 forces the valve member 90 to the upper position thereof, as shown in the drawing, thereby opening ports 86 so that the fluid is forced through passage 88 and line 94 into the bore 16. The pressure provided by the booster unit 108 is greatly increased above that at which the fluid is normally maintained within the tank 70 and forces the piston 22 of the piercing unit to its extended position to perform the piercing operation. The stripper member 54 is normally held in an extended position relative to the punch 38 by the spring 56 and during the working stroke of the unit the stripper member may engage the work 130 to clamp the same against the die 132 prior to engagement of the work by the punch 38. As the piston 22 continues to move the piston rod 30 slides on the balls 66 through the stripper member 54 carrying the punch 38 into the work. When the piercing operation is completed, the valve 122 is adapted to connect the line 124 to the exhaust line 126 whereupon the booster pistons will be returned to their lower position in the manner described and the valve member 90 Will return to its lower position thereby opening ports 84. The return spring 52 then returns the piston 22 to its retracted position forcing the hydraulic fluid in the bore 16 back through line 94, passage 88, ports 84, passage 76 and line 74 to the tank 70.

The punch 38 can be removed from the end of the piston rod 30 by removing the set screw 40 and then rotating the stripper member 54 until the slot 64 therein is arranged opposite the ball 66, whereupon the ball is removed from the groove 62 and after each of the balls has been removed the stripper member is slid off of the end of the piston rod. The punch 38 can then be removed from the socket 36. In setting up the piercing unit it is frequently necessary that the punch be properly oriented relative to the die member 132 such as when the punch and die openings are of irregular shape. This can be easily accomplished in the piercing unit of this invention by unplugging the conduit 94 from the end plate 18 and then inserting a tool through the threaded opening into the socket in the head of the screw 28 and then rotating the piston 22 until the punch is properly oriented relative to the die member. The collar 42 will be rotated with the piston and, when the proper angular adjustment is attained, the set screw 134 is tightened against the collar 42 to lock the piston unit and the punch carried thereby in the adjusted position. After the stripper member 54 has been removed in the manner described, the entire piston unit can be removed from the body 14 by removing the end plate 18 and withdrawing the piston unit from the open end of the bore 16. The spacer sleeve 50 limits the stroke of the punch 38 and may be replaced with a sleeve of different length to alter the stroke of the punch.

The hydraulic control system described herein is disclosed in my copending application Serial No. 832,720 filed August 10, 1959, now Patent No. 3,089,375 of which the instant application is a continuation-in-part. It will be apparent that other control systems may be used with the piercing unit of this invention and that any of the other control systems shown in said copending application may be used if desired.

While I have illustrated and described a preferred embodiment of my invention, it is understood that this is capable of modification, and I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. A hydraulically actuated piercing unit comprising a body having a cylinder bore opening from one end thereof, a detachable end plate closing the open end of said bore, a fluid'connection through which fluid is supplied to said bore, a piston reciprocable in said bore, a rod secured to said piston and extending through and projecting from the other end of said body, a collar in said body through which said piston rod extends, said piston rod being nonrotatable relative to said collar, a socket in the outer end of said piston rod, a punch having one end disposed within said socket and projecting therefrom for cooperation with a die member, means for locking said collar in an adjusted angular position thereof to said body for orienting said punch relative to said die member, a sleeve-like stripper member enclosing and slidably mounted on the outer end of said piston rod, an annular grooveon the inner Wall of said stripper member, a ball seated in a recess on said piston rod and in said groove for limiting sliding movement of said stripper member on said piston rod, a spring reacting on said stripper member and the end of said piston rod for biasing said stripper member to an extended position relative to said piston rod for clamping the work against the die member prior to engagement of the punch with the work upon actuation of said piercing unit, a slot in the side of said stripper member intersecting said groove, and a pin insertable through said slot and through said piston rod into engagement with said punch whereby upon removal of said pin said stripper member may be rotated to bring said ball into registry with said slot whereby said ball may be removed through said slot and said stripper member may be axially removed from said piston rod.

2. A piercing unit according to claim 1 including a spacer sleeve in said bore between said collar and said piston for limiting movement of said piston, said means for locking said collar in an adjusted angular position comprising a keyed connection between said collar and said piston rod.

References Cited in the file of this patent UNITED STATES PATENTS 532,265 Cornell Ian. 8, 1895 1,914,313 Wales June 13, 1933 2,112,153 Gorham Mar. 22, 1938 2,168,377 Wales Aug. 8, 1939 2,227,081 Gray Dec. 31, 1940 2,760,574 Taylor Aug. 28, 1956 3,064,514 Wilson Nov. 20, 1962 3,079,824 Schott Mar. 5, 1963 

1. A HYDRAULICALLY ACTUATED PIERCING UNIT COMPRISING A BODY HAVING A CYLINDER BORE OPENING FROM ONE END THEREOF, A DETACHABLE END PLATE CLOSING THE OPEN END OF SAID BORE, A FLUID CONNECTION THROUGH WHICH FLUID IS SUPPLIED TO SAID BORE, PISTON RECIPROCABLE IN SAID BORE, A ROD SECURED TO SAID PISTON AND EXTENDING THROUGH AND PROJECTING FROM THE OTHER END OF SAID BODY, A COLLAR IN SAID PISTON ROD BEING NONROTATABLE RELATIVE TO SAID COLLAR, A SOCKET IN THE OUTER END OF SAID PISTON ROD, A PUNCH HAVING ONE END DISPOSED WITHIN SAID SOCKET AND PROJECTING THEREFROM FOR COOPERATION WITH A DIE MEMBER, MEANS FOR LOCKING SAID COLLAR IN AN ADJUSTED ANGULAR POSITION THEREOF TO SAID BODY FOR ORIENTING SAID PUNCH RELATIVE TO SAID DIE MEMBER, A SLEEVE-LIKE STRIPPER MEMBER ENCLOSING AND SLIDABLY MOUNTED ON THE OUTER END OF SAID PISTON ROD, AN ANNULAR GROOVE ON THE INNER WALL OF SAID STRIPPER MEMBER, A BALL SEATED IN A RECESS ON SAID PISTON ROD AND IN SAID GROOVE FOR LIMITING SLIDING MOVEMENT OF SIAD STRIPPER MEMBER ON SAID PISTON ROD, A SPRING REACTING ON SAID STRIPPER MEMBER AND THE END OF SAID PISTON ROD FOR BIASING SAID STRIPPER MEMBER TO AN EXTENDED POSITION RELATIVE TO SAID PISTON ROD FOR CLAMPING THE WORK AGAINST THE DIE MEMBER PRIOR TO ENGAGEMENT OF THE PUNCH WITH THE WORK UPON ACTUATION OF SAID PIERCING UNIT, A SLOT IN THE SIDE OF SAID STRIPPER MEMBER INTERSECTING SAID GROOVE, AND A PIN INSERTABLE THROUGH SAID SLOT AND THROUGH SAID PISTON ROD INTO ENGAGEMENT WITH SAID PUNCH WHEREBY UPON REMOVAL OF SAID PIN SAID STRIPPER MEMBER MAY BE ROTATED TO BRING SAID BALL INTO REGISTRY WITH SAID SLOT WHEREBY SAID BALL MAY BE REMOVED THROUGH SAID SLOT AND SAID STRIPPER MEMBER MAY BE AXIALLY REMOVED FROM SAID PISTON ROD. 